WebApi EF Core 2.1 Code First 设置导航属性,外键

 public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
            services.AddDbContext<AppDbContext>(options =>
            {
                options.UseSqlServer(Configuration.GetConnectionString("SqlConnection"));
            });

            var serviceProvider = services.BuildServiceProvider();

            using (var context = serviceProvider.GetService<AppDbContext>())
            {
                context.Database.Migrate();
            }
        }

 protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Student>().HasData(new List<Student>() {
                new Student() {  age=3, id=1, name="T" ,TeacherId=2}
                ,new Student() {  age=3, id=2, name="S" ,TeacherId=2}
               , new Student() {  age=3, id=3, name="F" ,TeacherId=1}
               , new Student() {  age=3, id=4, name="D" ,TeacherId=3}
            });
            modelBuilder.Entity<Teacher>().HasData(new List<Teacher>() {
                new Teacher() {  age=3, id=1, name="T1"}
                ,new Teacher() {  age=3, id=2, name="S2"}
               , new Teacher() {  age=3, id=3, name="F3"}
               , new Teacher() {  age=3, id=4, name="D4"}
            });
            base.OnModelCreating(modelBuilder);
        }